Survival improvements in patients with melanoma brain metastases and leptomeningeal disease in the modern era: Insights from a nationwide study (2015–2022)

Introduction: Advances in modern therapies have improved outcomes for patients with melanoma brain metastases (MBM), though prognosis remains poor. The optimal treatment strategy for patients who do not meet clinical trial inclusion criteria is unclear. Methods: This study included all patients with MBM diagnosed in Denmark between 2015 and 2022, identified through the Danish Metastatic Melanoma Database (DAMMED) and local surgical and radiotherapy records. Data were collected from electronic patient records. Results: A total of 838 patients were included, with a median overall survival (OS) of 9.0 months. Of these, 112 (19.4 %) survived beyond 3 years post-diagnosis. Patients treated with immune checkpoint inhibitors (ICI) as first line treatment, specifically ipilimumab + nivolumab, demonstrated an intracranial overall response rate (icORR) of 46 % and a 2-year OS of 49 %. Those treated with BRAF/MEK inhibitors (BRAF/MEKi) had an icORR of 56 % but a 2-year OS of 20 %. Patients with leptomeningeal disease (LMD, n = 67) had a median OS of 8.4 months. Systemic therapy was associated with a superior OS for patients with LMD, though no survival benefit was seen with ICI compared to BRAF/MEKi. Among the 230 patients who underwent surgery, 30 received postoperative stereotactic radiosurgery (SRS); however, there was no difference in OS or intracranial progression-free survival between the groups. Conclusion: A considerable proportion of patients with brain metastases diagnosed after 2015 survived more than 3 years. Patients with LMD appeared to obtain limited benefit of ICI with only few patients alive > 3 years post-diagnosis.